Sure we can help!
All you need is this cable found here,
HARNESS-AUXILIARY AUDIO - iPod Harness :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com or check your local Nissan dealer. They might have it in stock. Your iPod will not charge tho, unless you get one of these,
Charging Adapter for iPod & iPhone
Hope this helps.
Oh, and you plug in that cord under the center arm rest.